Grant Shapps aka Michael Green says claims he altered his Wikipedia entry have been 'blown out of all proportion'. Photograph: Graeme Robertson for the Guardian

Conservative party co-chairman Grant Shapps has attempted to explain in a television interview why he had used an alter ego as a businessman, and insisted he was not living a double life.

While he was a senior Tory MP who attended shadow cabinet meetings, Shapps also presented himself as Michael Green, apparently a millionaire web guru, who claimed that customers could make $20,000 (£12,373) in 20 days with the help of his online guides – priced at $497.

Shapps with his wife Belinda founded, owned and ran an internet marketing company, How To Corp, until 2008. The MP said it was normal practice to use a pen name after the Guardian printed a picture of him attending an internet conference, shortly before he was elected to parliament, wearing a "Michael Green" name badge.

It prompted claims by Labour MP Steve McCabe that Shapps had "multiple personalities and questionable business practices" while Lord Prescott dubbed him "two tags" – a reference to his own nickname of "two Jags".

Shapps told Dermot Murnaghan on Sky News: "Before I went into parliament I used to write business publications, and like many authors wrote under a business name. I was always very open about it and I actually went to one conference, where that picture was from, it was sort of open fact. It was in my biography, it was in the conference programme.

"I have seen some extraordinary headlines though, things about living double lives as though I was François Mitterrand with his second family and things.

"My wife and I set up the business, we were always very open about it and had a business author's name as many authors do. It was all a long time ago, I've not been involved for a long time."

Shapps also said that claims he had altered his entry on Wikipedia were "blown out of all proportion", saying he had simply corrected it after someone gave him higher exam grades than he had achieved and incorrectly stated he was a Jehovah's Witness.

Also gone were references to his apparent role in a 2007 byelection in west London where he impersonated Liberal Democrats online in an attempt to discredit his rivals – but forgot that he had logged on as himself. He later claimed someone had hacked into his account.

The campaign was notable as Shapps was then a vice-chair of the Conservative party responsible for campaigning. The Tory candidate came third when many felt he was favourite to win. However, the episode was airbrushed away on the online encyclopaedia.

Almost all of Michael Green's websites have now disappeared from the internet – as has How To Corp's premier product, TrafficPaymaster, which created an instant cashflow for websites by appearing to plagiarise information. Google, the internet giant, banned websites created by How To Corp's product, which Shapps says was created in 2010, two years after he transferred his share in the family firm to his wife.